Background: Enterprise Resource Planning (ERP) software was originally conceived for manufacturing contexts and has later been generalized to cover service contexts as well. In hospitals, adoption was accelerated by an increasing commodification and marketization of health care.

Question: What impact do the manufacturing roots of SAP ERP have when the software is applied for service delivery in a hospital?

Method: A typical-case Yin Case Study about the surgery planning and execution processes in a large university hospital.

Results: One goal of the ERP implementation was to optimize the utilization of the operation rooms (ORs). This goal was largely missed because of too-low quality of planning data effectuated intentionally by the surgeons in order to pursue micropolitical agendas. This was possible because the software paid no attention to micropolitics at all, largely due to its roots in manufacturing and hidden by higher software layers that claimed to be adapted to the hospital domain.

Conclusions: Apparently, successful complex reusable application software can create a domain paradigm that subsequently creates product risk by being inappropriately and neglectfully extended into other domains where it does not apply. Software engineering should become aware of this effect and perform research to control it.